The present invention relates to soft touch fibers and nonwoven fabrics made from such fibers. The fibers comprise an incompatible polymer system which leads to the soft touch quality.
Polypropylene nonwoven fabrics are used in many medical and hygiene applications. For these purposes, the material must not only meet mechanical requirements, but must also have acceptable feel and appearance. For quite some time, there has been a desire to make polypropylene nonwovens with cloth-like aesthetics, as polypropylene nonwovens are often described as oily and plastic-like. One approach to change the tactile perception of polypropylene nonwovens is to change the surface texture of the fibers.
Incompatible blends have been used to form fibers with an irregular fiber surface. These fibers have a distinctly different feel. However, they have poor mechanical properties and are difficult to spin. It has been discovered that using these blends as the outer layer of a fiber, for example as the sheath component in a bicomponent fiber gives the desired feel while the core can provide the spinnability and mechanical properties.
The present invention involved forming fibers from a series of immiscible blends and quantifying the fiber properties of the resulting fibers. The results provide an understanding of the parameters that affect the fiber morphology, ultimately leading to controlling the fiber surface structure to obtain desired aesthetic properties.